﻿//-----------------------------------------------------------------------
// <copyright file="CompoundAction.cs" company="Nathan Miller">
// Copyright (c) Nathan Miller.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// </copyright>
//-----------------------------------------------------------------------
namespace TileTool.Action
{
    using System;
    using System.Collections.Generic;

    /// <summary>
    /// An action that is a collection of other actions.
    /// </summary>
    public class CompoundAction : ActionBase
    {
        #region Fields - Private

        /// <summary>
        /// List of actions we are managing.
        /// </summary>
        private IList<IAction> actionList = new List<IAction>();

        #endregion

        #region Constructor

        /// <summary>
        /// Default constructor.
        /// </summary>
        public CompoundAction()
        {
            this.Valid = false;
        }

        #endregion

        #region Methods - Public

        /// <summary>
        /// Add an action to the compound action.
        /// </summary>
        /// <param name="action">Action to add.</param>
        public void AddAction(IAction action)
        {
            if (action == null)
            {
                throw new ArgumentNullException("action", "Action must be non-null.");
            }

            if (this.actionList.IndexOf(action) != -1)
            {
                throw new InvalidOperationException("Attempting to add the same action twice.");
            }

            this.actionList.Add(action);

            this.Valid |= action.Valid;
        }

        /// <summary>
        /// Do the action.
        /// </summary>
        public override void Do()
        {
            if (!this.Valid)
            {
                return;
            }

            foreach (IAction action in this.actionList)
            {
                action.Do();
            }
        }

        /// <summary>
        /// Undo the action.
        /// </summary>
        public override void Undo()
        {
            if (!this.Valid)
            {
                return;
            }

            for (int i = this.actionList.Count - 1; i >= 0; --i)
            {
                IAction action = this.actionList[i];

                action.Undo();
            }
        }

        #endregion
    }
}
